JP 2002-59026A (Patent Document 1) discloses a mixture separation method using a magneto-Archimedes effect. The mixture separation method disclosed in Patent Document 1 is characterized in that a magnetic field having a magnetic field gradient (referred to as “gradient magnetic field” hereinafter) is applied to a plastic mixture including a plurality of types of diamagnetic solid plastic particles that floats or sinks in a paramagnetic supporting liquid to float the plastic particles at positions corresponding to the types of particle.
On the other hand, a high gradient magnetic separation (HGMS) method as disclosed in JP 2004-533915A (Patent Document 2) is known as a method for adsorbing and separating particles of paramagnetic materials (feeble magnetic materials) in liquid or gas. In the HGMS method, a high gradient magnetic field is generated by applying a high magnetic field to a magnetic filter formed of fine wires of a ferromagnetic material to adsorb paramagnetic particles in liquid or gas on the magnetic filter.